Fighting wildfires is more than a matter of pointing hoses at the flames and hoping for the best. Just like military generals, fire chiefs study the battlefield, predict the enemy's moves, and deploy troops to vulnerable flanks.

It helps that fires tend to follow well-known rules. Still, models based on decades of research are often unable to predict a fire's path when weather conditions get in the way. Fire strategy and high-tech devices haven't been able to stop blazes from wreaking havoc in southern California, pointing to the limits of fighting and forecasting wildfires, especially in a region where gusts of dry winds change direction and speed up with no warning.

Case in point: San Diego's mammoth Cedar Fire grew at amazing speeds, allegedly caused by hunter shooting a signal flare into the air east of the city. Whipped by the region's perennial Santa Ana winds, the fire moved too fast to allow firefighters to forecast its path and surround it.

"You've got a fire that went from 1,000 acres to 115,000 in 12 hours," says Bob Wolf, president of the California Department of Forestry firefighters' union. "I've been a firefighter for 22 years and I've never seen anything like it."

Indeed, for the crews throughout southern California, this week's blazes represent what many call a "career fire" - an epic battle that will stay with them through their lives.

The deployment of resources was massive, but also not enough to prevent devastation. Some 10,000 firefighters worked throughout the state.

Gov. Gray Davis activated the California National Guard and called for firefighters from out of state. Early Tuesday, some fire trucks and helicopters were on the way from Arizona and Nevada. President Bush declared four counties disaster areas, qualifying them for federal aid.

For the first time in almost two decades, the San Diego Fire Department issued an "all-call," ordering all off-duty firefighters to report to work. Many reported to work at 5 a.m. Sunday and didn't take a break until midnight, coping not only with the stress of firefighting but also the unheralded exertion required to move to new locations. "You lay a great deal of hose when you're trying to fight [part of] a fire, and once it's knocked down you have to pick up that equipment and move onto the next location," says San Diego Fire Capt. Ron Saathoff. "It's very ... labor-intensive."

By Tuesday morning, fires in the region had blackened 500,000 acres - approaching the size of Rhode Island - and destroyed 1,100 homes. Tens of thousands of residents had been evacuated as a dozen blazes roared. At least three San Diego firefighters lost their own homes.

Local citizens, while lauding the efforts of fire crews, also expressed frustration.

Luis Ochoa, leaning against a car packed with photo albums, clothes, and jewelry, watched a blaze near his San Diego race up a hill and observed: "I don't think they have the resources to handle this size of catastrophe."

Indeed, the battle is costing the state more than $5 million a day - heading toward a total that could reach $100 million.

"The fire forces in California have aggressively pursued every fire in the state as soon as possible with everything we could bring to bear," says Dallas Jones, director of the state's Office of Emergency Services. "You have to understand though, that with this number of wind-driven fires you ultimately run out of resources."

Along with satellite reconnaissance and sensors that detect the hottest areas of wildfires, global-positioning systems (GPS) devices are on the cutting edge of firefighting technology. Pilots use them as well. "Instead of putting a map on your knee and looking out the window, you can just let the GPS do it," says Mark Finney, a federal fire researcher in Missoula, Mont. More accurate communication about locations helps to deploy firefighters and aircraft - which were able to save some structures with strategic dumps of fire retardant.

But most fire department strategists must rely on other skills, especially if aircraft are scarce, as they have been in the San Diego fires. "The fire manager is a geologist, ecologist, and meteorologist, sort of all rolled up into one," says wildfire consultant John Rogan, professor of geography at Clark University in Worcester, Mass.

Firefighters like to repeat a mantra of the three major factors in the progress of any wildfire - fuel, topography, and weather. Southern California can turn fire-friendly in a matter of hours, when winds gust through mountain passes, into valleys, and up canyon walls, and humidity drops below 25 percent. Flames also love slopes - the steeper the better. And in this case, windy weather made it hard to use "backfires" to cut off fires' progress.

Firefighters are finding hope in the form of another mantra, though: The hot Santa Ana winds usually don't last beyond 72 hours. As of Tuesday, the winds were diminishing and forecasters saw cooler weather in coming days. The state's rainy season is just around the corner.

But the topography never changes. The steep slopes remain, waiting to be in the wrong place at the wrong time.

• Janet Saidi in San Diego contributed to this article, and AP material was used.